After a three day listening orgy, with much to go before I revisit my whole collection, I will pronounce these the Last Word. I have a broad collection of 'phones at a lot of quality and price levels for acoustic measurement but and these are the first I've encountered that I will call...

I'm asking for headphone recommendations where the primary criteria are comfort and low cost in that order.  I need low non-linear distortion but the frequency response matters little so long as there are no absurdly deep nulls.